Mechanical time comparator mechanism



DCC 22, 1953 M. E. BUEHLER MECHANICAL TIME COMPARATOR MECHANISM 2 Sheets-Sheet l Filed Dec. 27, 1951 Dec. 22, 1953 M. E. BUEHLER 2,663,863

MECHANICAL TIME COMPARATOR MECHANISM Filed Deo. 27, 1951 2 Sheets-Sheet 2 BVM am Patented Dec. 222,Y 1953 MECHANICAL TIME COMPARATOR MECHANISM Maurice E. Buehler, San Diego, Calif. Application December 27, 1951, Serial No. 263,679

4 Claims.

(Granted under Title 35, U. S. Code (1952),

Sec.

The iir-Jention described herein may be manul'actured and used by or ior the Government for vernrnental purposes without payment to nie or" any royalty thereon.

rThis invention relates to a synchronism detector incre particularly to a synchronisrn detector wherein a voltage is produced whose poiarity is function oi the seouei'ice o two periodic phenomena and whose afpiitude is a iunction of the time difference between the two .odio phenomena.

the of rca-ny systems oitens desirable and even essfutial that periodic mena such as two rota g in-embers, two

tining of two periodic phenomena.

another object of this invention to ro vide a synchronisrn detector which will pr duce oil a signal whose polarity will be a function of e sequence oi two periodic phenomena.

The above objects as well as other objects, features and advantages of this invention will be more clearly understood. in View of the following description when taken in conjunction with the drawings wherein:

Fig. .i is arrscheniatic diagram of an embodiment of this invention as applied to detection of synchronisni between two rotating members.

Figs. 2 and 3 are diagrams explaining the operation of the apparatus in Fig. l.

Fig. l is the output voltage characteristic of the apparatus oi Fig. l.

Referring now to the drawings and more particularly to Fig. l thereof, a control member I is pivotally mounted on pivot 2 for movement into either one of two opposite positions. The control member I is provided with an arm 3 to which is attached a biasing mechanism Il which will cause the control member to move into a nrst stable equilibrium position when the control member is unbalanced in one direction, for eX- ainple to the left as viewed in the Fig. i and will cause the control member to be moved into a second position of the equilibrium when the control member l has been unbalanced in a second direction, for example to the right as viewed in Fig. 1. Although the biasing of the control member I above described has been illustrated as being of the over center spring type, it will be understood that other types of biasing such as magnetic biasing may be employed.

When the control member i is unbalanced to the left as viewed in Fig. i. a first set of contacts E are closed and when the controi member i has been unbala c. to the as viewed in Fig. 1 a second set oi` contacts are ciosed.

in order to cause the control member I to be unbalanced to the left in response to a periodic phenomenon, such as the rotation of a shaft, a cani i mounted on the shaft S actuates the i ich through a suitable lever and linkage l produces a force on the control meinto cause the control member to unbalanced to left as viewec in 'i The shaft it has attache. thereto a cam I2 which actuates the member which through a suitable lever iiy kage systen. Ifi produces a force on the control member i to cause that member to lbe unbalanced to the right as viewed in Fig. i.

when the contacts 5 are closed current flows from a suitable source of electrical potential i5 through the resistor an' when the contacts 6 are closed current rlows from potential source E55 through a resistor The potential developed across the resistors and il is used to actuate a suitable indicating device such as the volt meter iB.

The operation oi" the apparatus shown in Fig. i may be understood by referring to 3 and 4. Referring to Fig. 2 the forces applied to the control member i throughL the lever linkage svtems I 3 and I4 consists of a series of spaced pulses separated by a time interval T with the B pulses lagging the A pulses by a sir-all time interval AT. Assuming the control ineinber I to be in a position ci balance or unstable equilibrium, the first A pulse acts to cause the control member to be unbaianced to the left thus closing contacts and causing a curent to iiow through the resistor i6. A short interval of time, AT, later, a B pulse occurs which causes the control member i to be unbalanced to the right causing contacts to close and contacts 5 to open. The voltage across the resistor IS will then drop to 0 the voitage across resistor il will drop from zero to a predetermined negative value and will remain there until the receipt of the next A puise.

By referring to the potential of resistors i6 and il in 2, it is seen that the average value of the voltage across the resistor I'l is greater than the average value across the resistor i6. The difference in these two voltages is used to actuate the meter it and the greater of these two voltages will determine the polarity aceaeca and thus the direction ci deflection of the pointer of the meter il.

The relationship between the voltage developed across the resistors i6 and l and AT is shown by Fig. Li. As shown by the discontinuity in the curve at AT=G it is seen that the appaiatus is highly sensitive to small values oi AT.

Eig. 3 illustrates the relationship in time of the input pulses and the potential across the resistors it and il when the input puise A leads the input pulse T3 by an amount W'hici'iis greater than the value of AT shown in Fig. 2.

One of the principal novel features of the ap paratus above described is the restoration of Ya unstable mecha ci to a ci eqn'v` caus'cg motion of this unstable system .in one direct on or the other by infinitesimal orders of time dinerence between the actnating periodic phenomena. The unstable mechanism in a se se may also be called regenerative mechani m, since the application of a very small unbalance due to time di erence in the phenomena causes a large force to Toe set up which. is in the same direction as the original infinitesimal small force. This :ehanical system is a close analogy of the electronic regenerative time comparator disclosed in No. 2,514,359, dated `July ll., i950, issued to E. Buehler.

Although this invention has been described and illustrated. as applied to phenomena, such as to rotating shafts, it Will be understood that the invention may be used to determine the synchronism between other periodic phenomena, such as electric signals, in which case forces which vare functions of those signals may be developed by l,

electro magnetios and these electro magnetics so arranged as to cause movement of the control member i.

What is claimed is:

i. A synclironism detector comprising a pivotably mounted control member, biasing means to cause said control member to tend to remain in a iii-st position when said control member has been unbalanced in one direction and to tend to remain in a second position when said control member has been unbalanced in the other direction, means to apply a first force to said control member to cause said control member to be unbalanced in said one direction in response to a first periodic phenomenon, means to apply a second force to said control member to cause said control member to be unbalanced in said other direction in response to a second periodic phenomenon, a first pair ci contacts operated by said control member and so arranged that they are closed when said control member is in saidA rst position and open when said control member is in said second position, a second pair of contacts operated by said control member and so arranged that they are open when said control member is in said first position and closed when said control member is in said second position, electrical indicator' means and circuit means including said first and second pair of contacts for energizing 'said electrical indicator means.

2. i synchronism detector comprising a pvotably mounted control memben biasing meansv to cause said control member to move into either one of two opposite positions of stable equilibrium, means to apply a first force to said control member to cause said control member to move into one of said two opposite positions in response to a first periodic phenomenon, means to cause said control member to move into the other of said two opposite positions in response to a second periodic phenomenon, a first pair of con* tacts operated by said control member and s0 arranged that they are closed When said control member is in said one position and open when said control member is in said other position, a second pair of contacts operated by said control member and so arranged that they are open when said control member is in said one position and closed when said control member is in said other position, and means for producing a voltage of one polarity When said first pair of contacts are closed and of opposite polarity when said second pair or" contacts vare closed.

3. A synchronism detector comprising a pivotably mounted control member, over center spring means to cause said control member to tend to remain in a rst position when said control member has been unbalanced in one direction and to tend to remain in a second position when said control member has been unbalanced in the other direction, means to apply a first force to said control member to cause said control member to be unbalanced in said one direction in response to a first periodic phenomenon, means to apply a second force to said control member to cause said control member to be unbalanced in said other direction in response to a second periodic phenomenon, a `first pair of contacts operated by said control member and so arranged that they are closed when said control member is in said i'st position and open When said control member is in said second position, a second pair of contacts operated by said control member and so arranged that they are open when said control member is in said first position and closed when said control member is in said second position, a source .of D. C. potential, a rst resistor, a second resistor, circuit means to connect said iirst resistor to said source of. l). C. potential when said iirst pair of contacts are closed, circuit means to connect said second resistor to said source of potential when said second set of contacts are closed and an electrical indicator connected across said rst re,- sistor and said second resistor.

li. A synchronism detector comprising a pivotally mounted control member, biasing means to cause said control member to tend to remainv in a nrst position when said control member has been unbalanced in one direction and to tend to remain in a second position When said control member has been unbalanced inthe other direction, means to apply a rst force to said control member to cause said control member to be unbalanced in said one direction in response to a iirst periodic phenomenon, means to apply a second force to said control member to cause said control member to be unbalanced in said other direction in response to a second periodic phenomenon, a iirst pair of contacts operated by said control member and so arranged that they are closed when said control member is in said nrst position and open When said control member is in said second position, a second pair of contacts operated by said control member and so arranged that they are open When said control member is in said nrst position and closed when said control member is in said. second position, means to produce a nrst potential having a predetermined polarity When said rst pairV of contacts are closed and to produce a second potential having a polarity opposite to said predeterapply a Second force t0 Said 001111101 member" 110 "g5 mined polarity when said secondpair of contacts are closed, an electrical indicator and circuit Number means to energize said electrical indicator with 1,510,410V said first potential and said second potential. 1,685,113 MAURICE E. BUEHLER. 2,246,516 5 2,412,605 References Cited in the file of this patent 2,555,491

UNITED STATES PATENTS Number Name Date N be 224,964 Stephenson Feb. 24, 1830 1511710325 1,058,051 Guest Apr. s, 1913 1 Name Date Gilman Sept. 30, 1924 Wilms Sept. 25, 1928 Herzog June 24, 1941 Drake Dec. 17, 1946 Hooven June 5, 1951 FOREIGN PATENTS Country Date Great Britain July 19, 1945 

